Cara: Mengatur Kebijakan Cache untuk Permintaan

Contoh berikut menunjukkan pengaturan kebijakan cache untuk permintaan. Contoh input adalah URI seperti http://www.contoso.com/.

Example

Contoh kode berikut membuat kebijakan cache yang memungkinkan sumber daya yang diminta digunakan dari cache jika belum berada di cache lebih dari satu hari. Contoh menampilkan pesan yang menunjukkan apakah sumber daya digunakan dari cache—misalnya, "The response was retrieved from the cache : False."—lalu menampilkan sumber daya. Permintaan dapat dipenuhi oleh cache apa pun antara klien dan server.

using System;
using System.Net;
using System.Net.Cache;
using System.IO;

namespace Examples.System.Net.Cache
{
    public class CacheExample
    {
        public static void UseCacheForOneDay(Uri resource)
        {
            // Create a policy that allows items in the cache
            // to be used if they have been cached one day or less.
            HttpRequestCachePolicy requestPolicy =
                new HttpRequestCachePolicy (HttpCacheAgeControl.MaxAge,
                TimeSpan.FromDays(1));

            WebRequest request = WebRequest.Create (resource);
            // Set the policy for this request only.
            request.CachePolicy = requestPolicy;
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            // Determine whether the response was retrieved from the cache.
            Console.WriteLine ("The response was retrieved from the cache : {0}.",
               response.IsFromCache);
            Stream s = response.GetResponseStream ();
            StreamReader reader = new StreamReader (s);
            // Display the requested resource.
            Console.WriteLine(reader.ReadToEnd());
            reader.Close ();
            s.Close();
            response.Close();
        }
        public static void Main(string[] args)
        {
            if (args == null || args.Length != 1)
            {
                Console.WriteLine ("You must specify the URI to retrieve.");
                return;
            }
            UseCacheForOneDay (new Uri(args[0]));
        }
    }
}

Imports System
Imports System.Net
Imports System.Net.Cache
Imports System.IO
Namespace Examples.System.Net.Cache
    Public Class CacheExample
        Public Shared Sub UseCacheForOneDay(ByVal resource As Uri)
            ' Create a policy that allows items in the cache
            ' to be used if they have been cached one day or less.
            Dim requestPolicy As New HttpRequestCachePolicy _
                  (HttpCacheAgeControl.MaxAge, TimeSpan.FromDays(1))
            Dim request As WebRequest = WebRequest.Create(resource)
            ' Set the policy for this request only.
            request.CachePolicy = requestPolicy
            Dim response As HttpWebResponse = _
             CType(request.GetResponse(), HttpWebResponse)
            ' Determine whether the response was retrieved from the cache.
            Console.WriteLine("The response was retrieved from the cache : {0}.", _
                response.IsFromCache)
            Dim s As Stream = response.GetResponseStream()
            Dim reader As New StreamReader(s)
            ' Display the requested resource.
            Console.WriteLine(reader.ReadToEnd())
            reader.Close()
            s.Close()
            response.Close()
        End Sub
        Public Shared Sub Main(ByVal args() As String)
            If args Is Nothing OrElse args.Length <> 1 Then
                Console.WriteLine("You must specify the URI to retrieve.")
                Return
            End If
            UseCacheForOneDay(New Uri(args(0)))
        End Sub
    End Class
End Namespace

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